Singulators are traditionally used to feed the fruit in single file to the fruit handling equipment. Singulators usually comprise two belts arranged in a V configuration to operate at different speeds to rotate the fruit and assist the fruit to form a single row ready for transfer onto the fruit handling equipment.
Fruit does not move at the average speed of the two belts but at a speed somewhere between the speed of the two belts. When the feed to the V belts is maximised a continuous line of fruit forms where the difference between the mean fruit size and the pitch of the fruit supports of the grader means that the speed of the singulator needs to be slowed down to prevent overfeeding of the grader conveyor. Therefore, as fruit is transferred from the singulator to the grader there is commonly a speed difference which can result in damage to the fruit due to impact with the fruit supports.
Furthermore, there is no control over spacing between the fruit in a row. Thus it is usual to either get a continuous row of fruit in end to end contact or if infeed is reduced, groups of touching fruit are produced with gaps there between. In other cases it is necessary to reduce the speed of the singulator belts to prevent overfeeding of the grader which often results in two or more fruit (doubles) being deposited into each fruit support thus preventing proper grading of the fruit. A consequence of slowing down the singulator belt speeds to prevent doubles is a corresponding increase in the speed differential between the grader and the fruit as it comes off the singulator and therefore an increase in the impact forces on the fruit. The optimum speed for good singulation of fruit into a single row is not always the same as the speed of the grader rendering it impractical to run singulator belts at speeds which match the speed of the grader.
It is these issues that have brought about the present invention.